Various different products are manufactured by first combining ingredients into a container, then sealing the container and effecting mixing of the contents. For example, pulverulent or liquid products are typically amenable to such production techniques.
One example of such production techniques occurs in the manufacture of paint. In order to manufacture paint, a liquid paint base is disposed within a container. Then various tinting agents or pigments and/or other additives are added to the paint base. The paint base and the pigments and/or other additives must then be thoroughly mixed so as to provide uniform color and/or various other properties throughout the contents of the container.
The addition of such pigments and/or other additives may be performed at either the facility of a local vender or at the manufacturing facility. In either instance, the pigments and/or other additives are commonly added to the paint base within a paint can, typically having either one or five gallon capacity, and the paint can is then vibrated or shaken in an attempt to thoroughly mix the contents of the paint can. Such mixing of the contents of the paint can may be performed by either bench-top mixers or floor-mounted mixers, both of which are operated by personnel who must insure that the container is properly sealed and securely clamped within the mixing apparatus. Operating personnel must also assure that the mixing process proceeds for an adequate length of time, so as to assure thorough mixing.
Examples of such manually operated mixing equipment are provided in U.S. Pat. No. 4,134,689 and U.S. Design Pat. No. D254,973. These patents disclose a floor-mounted apparatus which is adapted to receive a container, the contents of which are to be mixed. An operator adjusts a motor-operated clamping mechanism so as to assure that an adequate clamping force is applied to the container. The operator then initiates the mixing cycle and thereafter unclamps and removes the container from the apparatus. The mixer typically shakes the paint container in a generally linear reciprocating fashion.
It is also known to mix paint utilizing a gyroscopic motion as described in U.S. Pat. No. 5,116,134, issued on May 26, 1992 to Edwards et al. and entitled AUTOMATED PAINT PRODUCTION APPARATUS, wherein the paint container is simultaneously rotated about two perpendicular axes.
Those skilled in the art will recognize that it is not uncommon for paint, paint cans, mixer parts, etc. to undesirably be propelled from the paint mixer, due to inadequate clamping, loosening of parts, etc. A housing is generally provided so as to surround the paint being mixed and the moving parts of the mixer in order to prevent damage to adjacent equipment and/or potential injury to nearby personnel in the event that a paint container or a part of the paint mixer loosens and is hurled by the rapidly moving parts of the mixer therefrom.
Although such contemporary paint mixers have proven generally suitable for their intended purposes, they possess inherent deficiencies which detract from their overall effectiveness in the marketplace. Such contemporary paint mixers require excessively long mixing times in order to assure adequate mixing of the paint base, pigments, and/or any additives. Indeed, some contemporary paint mixers, particularly those utilizing linear reciprocating motion, frequently provide inadequate mixing of the paint base, pigment, and/or additives. Such inadequate mixing frequently results since the heavier pigments may remain relatively stationary due to the effects of inertia, as the paint base is moved back and forth relative thereto, resulting in insufficient mixing thereof.
As such, it is desirable to provide a paint mixer which mixes paint base, pigment, and/or any additives thoroughly and in substantially less time than that required by contemporary mixers.
Furthermore, contemporary mixers typically utilize clamping mechanisms wherein a lead screw, typically driven by an AC motor, effects movement of two clamping members toward one another. As those skilled in the art will appreciate, contamination of the lead screw, typically resulting primarily from spilled or splashed paint, reduces the effectiveness of the lead screw to properly effect clamping of the paint container. Contaminants typically adhere to the threads of the lead screw and harden so as to inhibit rotation of the lead screw through an associated threaded countermember or nut and also frequently provide a false indication of proper clamping. Thus, a contemporary clamping mechanism may sense reduced or non-rotation of the lead screw, due to contamination thereof, and incorrectly interpret such sensing as tight or proper clamping of the paint container.
Therefore, an inadequately clamped paint container may be shaken when utilizing a contemporary paint mixer having a soiled or contaminated lead screw. The shaking of such an inadequately clamped container is likely to result in further spillage and/or splashing of the paint, consequently resulting in further contamination of the lead screw, thus perpetuating the problem.
As such, it is beneficial to provide a clamping mechanism which is not subject to lead screw contamination, and which consequently does not result in improper clamping of the paint container.
Thus, although such prior art mixers have proven generally suitable for their intended purposes, they posses inherent deficiencies which detract from their overall effectiveness in the marketplace.
Additionally, contemporary paint mixers utilize an AC motor to effect actuation of the clamping mechanism thereof. Motor current is monitored so as to provide an indication that adequate clamping has been achieved. Such use of AC motors is common due to the availability of AC current, i.e., wall outlets. However, the monitoring of current in such AC motors does not provide as good an indication of proper clamping as would the monitoring of motor current for a DC motor utilized in a like application. As such, it is desirable to provide a fluidic mixer utilizing a DC motor to effect clamping of a container therein, wherein the motor current is monitored so as to provide an accurate and reliable indication of proper clamping.